This invention that is described in South African provisional patent specification No. 9710946, dated of Dec. 5, 1997, primarily relates to means to convey fluid from a moving location to a fixed location formerly achieved by the utilisation of such means as a flexible hose.
Flexible hoses have limitations in that they are substantially inelastic and have to be provided in sufficient length to accommodate the maximum distance between a moving and fixed location entailing the expense and inconvenience of supporting the hose under maximum distance and the difficulty of accommodating the same hose when the distance is reduced to a minimum.
An object of the invention is to overcome the shortcomings of flexible hose under these conditions
The invention has particular relevance to desludge systems where settled sludge suction takeup means is caused to traverse the floor of a settling tank or vessel and transmit the sludge via a hose to a disposal point and is particularly applicable to the desludge system described in U.S. Pat. No. 5,366,638, U.K. patent No 2 288 747 and S. African patent No. 92/5890. (R. P. Moore).
The invention provides improved means replacing flexible hoses and further can provide means to motivate the travelling sludge take up means.
In a further aspect of the invention the said conveyed fluid is utilised to drive or motivate a reciprocating sludge takeup system in one instance directly adapting the said means and in another instance utilising the said means.
According to the invention, a process for conveying fluid comprises a telescopic conduit, in which one or more hollow or conduit tubes, with in between sealing means, slide within each other, and provide means for conveying fluid from a movable point to a fixed point.
Further according to the invention, in any tank that accumulates sludge on the floor this telescopic conduit system comprises the means to convey the sludge from a movable sludge uptake system to any fixed point in the tank from where the sludge may exit the tank and be disposed of as required.
In a first example of the motivation or drive aspect of the invention, the difference in diameter between an outer and an inner conduit of the telescopic system is increased to provide, on the said sealing means, an area subject to differential pressure or suction from the conveyed fluid and the resulting force thereon is utilised to motivate or drive the sludge uptake system.
In a second example of the motivation or drive aspect of the invention, the flow of conveyed desludging liquid drives a rotary vane hydraulic motor that in turn motivates the trolley of a reciprocating travelling sludge uptake system via reduction drive means.
In a further description of the basic invention a means to convey fluid between a movable and a fixed location, comprises a lengthwise expandable and contractible telescopic conduit including an outer tubular conduit member connected at one end to a fixed fluid transfer receiving location and threaded from its opposite end by an inner tubular conduit member in turn connected at its opposite end to a movable fluid delivery source or vice versa with slidable sealing means between the inner and the outer tubular conduit members and between which intermediate telescopic conduit members may be provided, the whole comprising means to transfer fluid from a movable to a fixed location or vice versa.
The interconnecting telescopic conduit of the invention may have two basic forms, a xe2x80x9clength-wisexe2x80x9d or xe2x80x9cend-onxe2x80x9d form where the fixed point lies in the direction of travel of the moving point and the conduit expands and contracts in the direction of travel of the moving point and in what may be described as a xe2x80x9csidewaysxe2x80x9d form where the fixed point is located at the side of the line of travel of the movable point and swivels to follow the path of the movable point, the telescopic conduit being provided with swivelling means at both the fixed and moving points and having its direction changing in accordance with the movement of the movable point. In both instances the telescopic conduit serves to replace flexible hose used to convey sludge in a desludging system such as that disclosed in South African patent No. 92/5890. (U.S. patent No. 5,366,638. U.K. patent No. GB 2 288 747 R. P. Moore).
Returning to the first claimed drive aspect of the invention, this drive aspect requires that the said seal (subject to the differential pressure when desludging) is located at and attached to the inner end of the sliding conduit further the invention would require two of the said differential (differential diameter) telescopic drive conduits, located, (offset from each other) at opposite ends of the line of drive (the said xe2x80x9cend-onxe2x80x9d arrangement of the telescopic conduits) in order to motivate in both directions in accordance with automatic transfer of the sludge flow to each conduit at the end of travel in each direction.
The automatic transfer of flow at the end of travel may be effected by the automatic change-over triggering of valves located (exterior to the tank from which sludge is being removed) at the discharge end of each conduit.
Each telescopic conduit would connect to individual sludge takeup means (such as a perforated pipe traversing the floor that would only be operational when it leads in the direction of travel). This latter and the provision of two sludge take up means one at each end of the system that carries them such as a trolley are described in the above mentioned Moore patents and are necessary to ensure complete sludge floor coverage while reducing the trolley travelling distance that reduces proportionately to the distance between the two takeup means. Ensuring that only the leading sludge take up means is operational during desludging is also an economic and efficiency factor.
Automatic change-over with change in direction requires an appropriate change-over valving system. The external system (external to the tank) described above can apply even when there is no drive element, providing there are two telescopic conduits which could then discharge at the same end. Where only a single telescopic conduit is involved, internal change-over valved means between the dual sludge take up means and their connection to the common telescopic conduit is required.